Input: uinput - use completions instead of events and manual

       wakeups in force feedback code.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 43 insertions, 38 deletions

diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
index 9c3d20073ae3..c3eebf593ab6 100644
--- a/drivers/input/misc/uinput.c
+++ b/drivers/input/misc/uinput.c
@@ -53,24 +53,23 @@ static int uinput_dev_event(struct input_dev *dev, unsigned int type, unsigned i
         return 0;
 }
 
-static int uinput_request_alloc_id(struct input_dev *dev, struct uinput_request *request)
+static int uinput_request_alloc_id(struct uinput_device *udev, struct uinput_request *request)
 {
         /* Atomically allocate an ID for the given request. Returns 0 on success. */
-        struct uinput_device *udev = dev->private;
         int id;
         int err = -1;
 
-        down(&udev->requests_sem);
+        spin_lock(&udev->requests_lock);
 
         for (id = 0; id < UINPUT_NUM_REQUESTS; id++)
                 if (!udev->requests[id]) {
-                        udev->requests[id] = request;
                         request->id = id;
+                        udev->requests[id] = request;
                         err = 0;
                         break;
                 }
 
-        up(&udev->requests_sem);
+        spin_unlock(&udev->requests_lock);
         return err;
 }
 
@@ -79,70 +78,78 @@ static struct uinput_request* uinput_request_find(struct uinput_device *udev, in
         /* Find an input request, by ID. Returns NULL if the ID isn't valid. */
         if (id >= UINPUT_NUM_REQUESTS || id < 0)
                 return NULL;
-        if (udev->requests[id]->completed)
-                return NULL;
         return udev->requests[id];
 }
 
-static void uinput_request_init(struct input_dev *dev, struct uinput_request *request, int code)
+static inline int uinput_request_reserve_slot(struct uinput_device *udev, struct uinput_request *request)
 {
-        struct uinput_device *udev = dev->private;
+        /* Allocate slot. If none are available right away, wait. */
+        return wait_event_interruptible(udev->requests_waitq,
+                                        !uinput_request_alloc_id(udev, request));
+}
 
-        memset(request, 0, sizeof(struct uinput_request));
-        request->code = code;
-        init_waitqueue_head(&request->waitq);
+static void uinput_request_done(struct uinput_device *udev, struct uinput_request *request)
+{
+        complete(&request->done);
 
-        /* Allocate an ID. If none are available right away, wait. */
-        request->retval = wait_event_interruptible(udev->requests_waitq,
-                                        !uinput_request_alloc_id(dev, request));
+        /* Mark slot as available */
+        udev->requests[request->id] = NULL;
+        wake_up_interruptible(&udev->requests_waitq);
 }
 
-static void uinput_request_submit(struct input_dev *dev, struct uinput_request *request)
+static int uinput_request_submit(struct input_dev *dev, struct uinput_request *request)
 {
-        struct uinput_device *udev = dev->private;
         int retval;
 
         /* Tell our userspace app about this new request by queueing an input event */
         uinput_dev_event(dev, EV_UINPUT, request->code, request->id);
 
         /* Wait for the request to complete */
-        retval = wait_event_interruptible(request->waitq, request->completed);
-        if (retval)
-                request->retval = retval;
+        retval = wait_for_completion_interruptible(&request->done);
+        if (!retval)
+                retval = request->retval;
 
-        /* Release this request's ID, let others know it's available */
-        udev->requests[request->id] = NULL;
-        wake_up_interruptible(&udev->requests_waitq);
+        return retval;
 }
 
 static int uinput_dev_upload_effect(struct input_dev *dev, struct ff_effect *effect)
 {
         struct uinput_request request;
+        int retval;
 
         if (!test_bit(EV_FF, dev->evbit))
                 return -ENOSYS;
 
-        uinput_request_init(dev, &request, UI_FF_UPLOAD);
-        if (request.retval)
-                return request.retval;
+        request.id = -1;
+        init_completion(&request.done);
+        request.code = UI_FF_UPLOAD;
         request.u.effect = effect;
-        uinput_request_submit(dev, &request);
-        return request.retval;
+
+        retval = uinput_request_reserve_slot(dev->private, &request);
+        if (!retval)
+                retval = uinput_request_submit(dev, &request);
+
+        return retval;
 }
 
 static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
 {
         struct uinput_request request;
+        int retval;
 
         if (!test_bit(EV_FF, dev->evbit))
                 return -ENOSYS;
 
-        uinput_request_init(dev, &request, UI_FF_ERASE);
-        if (request.retval)
-                return request.retval;
+        request.id = -1;
+        init_completion(&request.done);
+        request.code = UI_FF_ERASE;
         request.u.effect_id = effect_id;
-        uinput_request_submit(dev, &request);
-        return request.retval;
+
+        retval = uinput_request_reserve_slot(dev->private, &request);
+        if (!retval)
+                retval = uinput_request_submit(dev, &request);
+
+        return retval;
 }
 
 static int uinput_create_device(struct uinput_device *udev)
@@ -189,7 +196,7 @@ static int uinput_open(struct inode *inode, struct file *file)
         if (!newdev)
                 goto error;
         memset(newdev, 0, sizeof(struct uinput_device));
-        init_MUTEX(&newdev->requests_sem);
+        spin_lock_init(&newdev->requests_lock);
         init_waitqueue_head(&newdev->requests_waitq);
 
         newinput = kmalloc(sizeof(struct input_dev), GFP_KERNEL);
@@ -551,8 +558,7 @@ static int uinput_ioctl(struct inode *inode, struct file *file, unsigned int cmd
                         }
                         req->retval = ff_up.retval;
                         memcpy(req->u.effect, &ff_up.effect, sizeof(struct ff_effect));
-                        req->completed = 1;
-                        wake_up_interruptible(&req->waitq);
+                        uinput_request_done(udev, req);
                         break;
 
                 case UI_END_FF_ERASE:
@@ -566,8 +572,7 @@ static int uinput_ioctl(struct inode *inode, struct file *file, unsigned int cmd
                                 break;
                         }
                         req->retval = ff_erase.retval;
-                        req->completed = 1;
-                        wake_up_interruptible(&req->waitq);
+                        uinput_request_done(udev, req);
                         break;
 
                 default: